A method of diagnostic imaging is disclosed comprising administering a medical formulation to a subject, the formulation comprising a contrast enhancement agent having structure I and salts thereof wherein R1 is independently at each occurrence a hydroxy group, a C1-C3 hydroxyalkyl group, or a C1-C3 alkyl group, and b is 0-4; R2-R7 are independently at each occurrence hydrogen, a C1-C3 hydroxyalkyl group, or a C1-C3 alkyl group, with the proviso that at least one of R1-R7 is a hydroxy group or a C1-C3 hydroxyalkyl group; and wherein Q is one or more charge balancing counterions; and one or more pharmaceutically acceptable carriers and excipients. The subject is subjected to a diagnostic imaging technique such as magnetic resonance imaging. The technique may be used in a variety of diagnostic imaging regimes, such as imaging of circulatory systems, genitourinary systems, hepatobiliary systems, central nervous systems, tumors, and abscesses among others.